Field of the Invention
The present invention relates to a display processing device and an imaging apparatus.
Priority is claimed on Japanese Patent Application No. 2014-100683, filed May 14, 2014, the content of which is incorporated herein by reference.
Description of Related Art
Imaging apparatuses such as cameras for still images or cameras for moving images generally have a function of displaying captured images on display devices. As the display devices, for example, there are display devices mounted in imaging apparatuses, such as a thin film transistor (TFT) liquid crystal display (LCD) or an electronic view finder (EVF). In addition, there are external display devices (external displays) connected to imaging apparatuses, such as a television (TV), a TFT monitor, or an organic electro luminescence (EL) display. As described above, as the display devices used to display images captured by the imaging apparatuses, there are various types of display devices having different frame rates or resolutions. Therefore, there is a demand for display processing devices provided in the imaging apparatuses and outputting image signals for display on display devices to be able to output image signals to various types of display devices. Furthermore, among the display processing devices, there are display processing devices employing a configuration including a plurality of display processing units in order to be able to simultaneously output image signals to a plurality of display devices.
In recent years, with the high definition of display devices, for example, TVs of a full HD size (1920×1080) (high definition TVs (HDTVs)) with higher definition than conventional TVs of a VGA size (640×480) have become mainstream in the field of TVs. Furthermore, recently, TVs of a 4K2K size (3840×2160) (ultra high definition TVs (UHDTVs)) with further higher definition have been commercialized. Therefore, there is a demand for display processing devices provided in imaging apparatuses to have further high performance.
For example, the case in which a display processing device that outputs an image signal of 60 frames per second (fps) with a full HD-size is adapted to be able to output an image signal of the 4K2K size at the same frame rate (that is, 60 fps) will be considered. In this case, in the 4K2K size, since the number of pixels to be displayed is four times that of the full HD size, a frequency of a clock (an operation clock) by which the display processing device operates is required to be four times that of the full HD size. Therefore, in the display processing device, the frequency of the operation clock becomes high, resulting in an increase in power consumption. Furthermore, in the development of the display processing device, since the display processing device is adapted to handle the high frequency of the operation clock, it is difficult to optimize operation timings of respective elements of the display processing device, that is, circuits for realizing the functions of the display processing device, and thus it is not easy to develop the display processing device.
For example, Japanese Unexamined Patent Application, First Publication No. 2006-053527 discloses a technology of a display processing device in which an entire area of an image of one frame is divided into a plurality of areas and the divided areas are processed in a parallel manner. In the technology disclosed in Japanese Unexamined Patent Application. First Publication No. 2006-053527, two display processing units are provided in the display processing device, an image area of one frame to be displayed is divided into right and left areas, and the respective display processing units process the left half image and the right half image in a parallel manner. In the technology disclosed in Japanese Unexamined Patent Application. First Publication No. 2006-053527, image signals processed by the respective display processing units are input in a parallel manner to a display device capable of receiving two image signals in a parallel manner, so that the entire image of one frame is displayed.
As described above, in the technology disclosed in Japanese Unexamined Patent Application, First Publication No. 2006-053527, the image area of one frame is divided into a plurality of areas to limit an increase in image areas to be processed by the respective display processing units, and the plurality of display processing units corresponding to the respective areas perform processing on the respective corresponding image areas in a parallel manner, so that a high definition image is displayed on a display device.
As the point of view of the technology disclosed in Japanese Unexamined Patent Application, First Publication No. 2006-053527 is used, a display processing device that outputs an image signal of the full HD size can be adapted to be able to output an image signal of the 4K2K size. In more detail, two display processing units corresponding to the full HD size are provided in the display processing device, an image of the 4K2K size is divided into two right and left images, and the respective display processing units process the left half image and the right half image in a parallel manner. In this way, the area of the images processed by the respective display processing units can be reduced to ½, and the frequency of an operation clock of the respective display processing units is increased twofold, so that it is possible to realize a display processing device that outputs an image signal of the 4K2K size.